Transport Systems

1)Bigger the organism-the further the oxygen has to travel,diffusion is a slow process-so the innermost would die cos it took oxygen so long to reach them 2)SA:Vol ratio decreases the bigger you are 3)Increased level of activity

1 of 13

Increasing level of activity?

larger animals more active generally-cos they have more cells : so there's a greater demand for oxygen/nutrients & to get rid of waste-but diffusion isn't sufficient enough

2 of 13

mass flow

movement of materials-with some sort of a force causing it e.g. blood flowing due to heart pumping

3 of 13

2 types of circulatory systems in vertebrates?

single & double- this refers to how many times the blood passes thru heart in one complete circuit of the body

4 of 13

Single Circulatory System (found in fish)

blood passes thru heart once per circuit. Deoxygenated blood pumped to Gills by heart, where it absorbs oxygen and excretes CO2. the oxygenated blood travels to other areas to deliver oxygen, before returning to heart

5 of 13

how many ventricles and atria does a heart have in a single circulatory system?

left:deals with oxygenated blood right: deoxygenated blood. Blood leaves right side of heart travels to lungs,gets oxygenated then goes to left side of heart-then pumped to organs and returns to right side again

8 of 13

What is the exception when the oxygenated blood from the organs doesn't return to heart?

oxygenated blood goes to gut-but then goes to liver via the hepatic portal vein before returning to heart

9 of 13

why is double better than single-evolutionary terms?

fish are older than mammals-so reasonable to think double c.system evolved from single-therefore it is an improvement of the single.

10 of 13

Advantages of double vs single c. system

Pressure+Speed of Blood drops in capillaries. in double, blood only travels thru once in capillary network but in single twice-therefore double maintains a higher pressure+speed-helps to maintain steep conc.gradients-makes exchange efficient

11 of 13

closed circulatory system (vertebrates)

blood circulates entirely within blood vessels

12 of 13

open circulatory system (insects)

blood is not always confined within blood vessels but also enters the body cavity